As electronic documents have come into widespread use in recent years, more and more people are reading electronic documents using electronic document readers. Many of the electronic document readers are equipped with a touch panel in which display functionality and input functionality are combined together.
When reading an electronic document, a user is required to perform an action, such as touching an icon, in order to turn displayed pages (to change displayed pages). Accordingly, actions are complicated by the user's eye movement. With the aim of eliminating the complication, various methods have been proposed about the page changing of the electronic document reader.
For example, PTL 1 discloses a display apparatus in which, when a given turning action is performed, a preset number of pages are turned to display. The number of pages turned at the same time is set by a distance over which multi-touching fingers have slid.
PTL 2 discloses an electronic book viewer which displays a cursor indicating the current read position in order to prevent a user from reading a wrong line or row. The electronic book viewer includes a page bar which visually shows where the currently displayed page is located in an electronic book. When a point displayed on the page bar is slid, pages are turned correspondingly.